i was looking at adding an urchin or two to my cube once its up n running. what i wanted to find out is this, are there any reef safe ones and what they feed on? from what i can remember they eat algea, and coraline algea as well. was looking at keeping one of those pic cusion types or and one with long spines, black type. any advise or comments here would be great.

Yeah, that was in my old 5ft, that urchin did nothing but poop everywhere and anything that was loose ended up on it's back, he was a right royal pain, although I must say he was excellent at cleaning the glass and rocks of algae.